1. Field of the Invention
The present invention relates to a magnetic tape library apparatus using magnetic tape cartridges as storage media. More particularly, the invention relates to a magnetic tape library apparatus having a bar code reader station for managing the magnetic tape cartridges loaded into the apparatus.
2. Description of the Related Art
Along with growing amounts of information to be processed by computer systems in recent years have come fully automated magnetic tape library apparatuses capable of accommodating and managing large quantities of magnetic tape cartridges without operator intervention. With many magnetic tape cartridges in storage in the library apparatus, the need is recognized for the ability to select any one of the stored cartridges using a bar code scheme.
There exist commercially available magnetic tape cartridges each comprising a substantially rectangular cartridge case, a magnetic tape wound inside the cartridge case, and a leader block attached to one end of the magnetic tape. The leader block is arranged to be engaged with one of the four corners of the cartridge case when the entire magnetic tape is wound therein.
Conventional magnetic tape library apparatuses illustratively have a bar code reader installed at their inlet port for admitting magnetic tape cartridges. When a magnetic tape cartridge is loaded into the magnetic tape library apparatus through the inlet port, the bar code reader reads the bar code attached to the magnetic tape cartridge before the cartridge is placed inside the apparatus.
One disadvantage of the above bar code scheme is that different magnetic tape cartridge suppliers attach the bar code label to a different location on each magnetic tape cartridge. This makes it difficult for conventional library apparatuses to read bar codes unfailingly from the cartridges that are used therewith.